Alzheimer's disease (AD) is the most prevalent form of dementing disorders in the aging population. The hypothesis of this program project proposal is that oxidative stress play an important role in the pathogenesis of AD. The development of animal models of AD has helped our understanding of the mechanisms involved in the disease process. The purpose of this Animal Core is to standardize and optimize the maintenance and breeding of the animals required in Projects 1 4 of this Program Project. The Animal Core Director and personnel are extensively trained in animal care and maintenance and in the techniques necessary for genotyping to determine the various strains of mice that will be used. The Animal Core will be responsible for the breeding protocols to establish mice required for execution of the studies outlined in this proposal. Additionally, the Core will be responsible for maintaining the background of the animals and providing the projects with the appropriate number of animals. This Core will help to integrate the use of animals between the different projects to prevent unnecessary duplication of animals and minimize the number of animals used to reduce costs. Centralization of the animal breeding and supply will increase the cooperation between projects, decrease the variability in data, and facilitate the comparison of results between the various projects.